1.5.7.1 Disk Groups

Disk groups are sets of mirrored or RAID5 configurations composed of shared disks. All data service and parallel database data is stored in disk groups on the shared disks. Mirrors within disk groups are generally organized such that each half of a mirror is physically located within a separate disk expansion unit and connected to a separate controller or host adapter. This eliminates a single disk or disk expansion unit as a single point of failure.

Disk groups may either be used for raw data storage, or for file systems, or both.